package cn.springcloud.alibaba.gateway.handler;

import cn.springcloud.alibaba.core.base.BaseResponse;
import lombok.extern.slf4j.Slf4j;
import org.springframework.http.HttpStatus;
import org.springframework.http.MediaType;
import org.springframework.stereotype.Component;
import org.springframework.web.reactive.function.BodyInserters;
import org.springframework.web.reactive.function.server.HandlerFunction;
import org.springframework.web.reactive.function.server.ServerRequest;
import org.springframework.web.reactive.function.server.ServerResponse;
import reactor.core.publisher.Mono;

import java.util.Optional;

import static org.springframework.cloud.gateway.support.ServerWebExchangeUtils.GATEWAY_ORIGINAL_REQUEST_URL_ATTR;

@Slf4j
@Component
public class FallbackHandler implements HandlerFunction<ServerResponse> {

	@Override
	public Mono<ServerResponse> handle(ServerRequest serverRequest) {
		Optional<Object> originalUris = serverRequest.attribute(GATEWAY_ORIGINAL_REQUEST_URL_ATTR);
		originalUris.ifPresent(originalUri -> log.error("网关执行请求:{}失败,降级处理", originalUri));

		BaseResponse response = new BaseResponse(-1, "网关降级");
		return ServerResponse.status(HttpStatus.OK.value())
			.contentType(MediaType.APPLICATION_JSON_UTF8)
			.body(BodyInserters.fromValue(response));
	}
}
